Languages such as Chinese, Thai, and Vietnamese are unique in that they are tonal languages. In a tonal language, each spoken syllable requires a particular pitch of voice in order to be regarded as intelligible and correct. For example, Mandarin Chinese has four tones, plus a “neutral” pitch. Cantonese Chinese has even more tones. These tones are described as “high, level,” high, rising” “low, dipping” and “high, falling” respectively, and may be noted as diacritical marks over Romanized versions of the Chinese sounds.
To mispronounce the tone is to miss the Chinese (or Thai or Vietnamese) word entirely. Therefore, in contrast to the English language, where pitch is used to a limited extent to indicate sentence meaning, for example to denote a question, Chinese uses tone as an integral feature of every word. Because of this, a tonal language spoken by a non-native speaker is often very hard for a native speaker to understand, because the tones are often mispronounced or misapplied.